JPH0334446B2 - - Google Patents

Abstract

PURPOSE:To improve the physical properties of a molded item by a method wherein resin impregnating, tack-free fiber as fiber reinforced plastic compression molding material is molded previously in a body of continuous section such as a round column, a square column, etc. to arrange long fibers having directivity in a specified part. CONSTITUTION:Member 1 is fiber reinforced plastic molding material wherein long fiber 1b is arranged in the vertical direction on the external circumference of short fiber reinforced plastic portion 1a, and is fiber that is impregnated with resin and tack-free. Before or after this mixture becomes tack-free, it is molded by a well-known continuous extrusion, etc. previously into continuous section body such as a round column, a square column. The above-mentioned material 1 is arranged between the top force 2 and the bottom force 3 and when the top punch 4 and the bottom punch 5 are approached to each other so that the top and bottom forces are not opened and welded under compression, the material 1 is deformed, melted and fills the space between the forces to form the shape of a molded piece 7.

Description

[Detailed Description of the Invention] Among the currently used methods for molding fiber-reinforced plastics, methods using long fibers include:
Examples include filament winding, continuous drawing, and continuous lamination.

However, none of these methods is a method for molding a molded article with a complicated shape. For this reason, when a gear has a complex shape and a long fiber arrangement along the tooth profile is desired on its surface, for example on the tooth surface,
It was manufactured by wrapping long fibers around the outer circumference of fiber-reinforced plastic in a cylindrical shape, integrating it, and cutting it.

This method not only has the drawback of requiring a large number of man-hours, but also requires cutting the long fibers, which are effective in terms of product strength, at important parts, halving the advantages of long fiber reinforced plastics.

In addition, injection molding is possible if the plastic is simply reinforced with short fibers, but the blending ratio of fibers is low. Furthermore, a method of cutting rod-shaped plastic reinforced with short fibers has been adopted, but the strength of the molded product is lower than that when using long fibers.

The present invention was proposed in order to eliminate such drawbacks, and it has been proposed to provide directionality to specific parts such as the outer periphery of a continuous cross-section body such as a cylinder or a prism formed from a tack-free material in which fibers are impregnated with resin. This invention relates to a material for compression molding of fiber-reinforced plastic, characterized in that a material made of long fibers having the following characteristics is disposed.

The fiber-reinforced plastic material for compression molding according to the present invention is prepared by preparing fibers impregnated with resin into a tack-free state (so-called B stage), and then forming the fibers into a tack-free state (so-called B stage).
Since it is formed by molding into a continuous cross-sectional body such as a prism, there are fewer air bubbles mixed into the material compared to other molding methods such as sheet molding compound, bulk molding compound, or lay-up method. Physical properties such as strength are improved, and variations in quality are reduced.

When compression molding is performed using the above material, the flow distance is short, so it is possible to smoothly flow and deform it with a smaller force than with normal compression molding, and therefore it is possible to mold complex shapes. Products can be molded with high precision, materials with high fiber content can be molded, burrs are less likely to occur, and the material yield is good. Furthermore, since a material with fewer pores can be used, the number of pores in the molded article is reduced, and a molded article with excellent physical properties can be obtained.

Furthermore, in the present invention, since the material made of long fibers having directionality is provided in specific parts where strength is required, such as the outer periphery of the continuous cross-sectional body such as the cylinder or prism, the strength and rigidity in the fiber direction is improved. In addition, physical properties such as wear resistance are strongly expressed, and the physical properties of the molded product are improved.

The present invention will be described below with reference to the illustrated embodiments.

1 is a fiber-reinforced plastic molding material in which long fibers 1b are arranged in the longitudinal direction on the outer peripheral surface of a short fiber-reinforced plastic part 1a, for example, fibers such as glass fiber, carbon fiber, aramid fiber, filler, mold release agent,
It is impregnated with resin such as unsaturated polyester, epoxy resin, vinyl ester resin, etc. mixed with hardening agent, condensing agent, thickener, coloring agent, etc. in advance to make it tack-free (so-called B stage). Before or after the tack-free process, it is preformed into a continuous cross-sectional body such as a cylinder, a prism, or a cylinder by a known continuous drawing method or the like.

The material 1 is placed between an upper mold 2 and a lower mold 3, and while the upper and lower molds 2 and 3 are not opened, the upper punch 4 is moved downward and the lower punch 5 is moved upward. When pressed, the material 1 deforms and flows to fill the cavity 6 in the mold and assume the shape of a molded product 7 as shown in FIG.

In this case, curing is completed by controlling the mold temperature and temperature application time using a known method according to the curing characteristics of the resin, and then the mold is opened and the molded product 7 is taken out.

In this way, according to this example, the material 1 is formed in advance into a continuous cross-sectional body such as a cylinder, a prism, a cylinder, etc., so there is less air bubbles mixed in compared to other forming methods, and physical properties such as strength are improved. improved, and the variation in quality is reduced. Furthermore, since force is applied near the portion to be deformed during compression molding, the force required for deformation is smaller than in normal compression molding methods, and it is therefore possible to mold materials with a high fiber content. Incidentally, for a molded product 7' as shown in FIG. 8, about half the force is required.

In addition, since the long fibers 1b having directionality are arranged in areas where strength is required, such as the outer periphery of the continuous cross-sectional body, strength and rigidity in the fiber direction are improved, and physical properties such as abrasion resistance are also strong. appears and improves the physical properties of the molded product.

Although the molding example using a closed mold has been described above, similar effects can be obtained using a normal non-closed mold.

Furthermore, regarding the form of the material 1, the long fibers 1b are arranged vertically on the outer periphery. The fibers 1b may be laminated or arranged outside the outer periphery.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the fiber-reinforced plastic compression molding material according to the present invention, FIG. 2 is a vertical cross-sectional view thereof, and FIG. 3 is a perspective view of a molded product formed from the material. Figures 4 and 5 are respectively 3rd
The arrow view of the figure and the arrow view, FIGS. 6 and 7 are longitudinal sectional views showing the molding process of the molded product,
FIG. 8 is a perspective view of another molded product made from the above material. 1...Fiber-reinforced plastic molding material, 1a...
...Short fiber reinforced plastic part, 1b...Long fiber.

Claims (1)

[Claims] 1. A fiber characterized by disposing a material made of long fibers with directionality in specific parts such as the outer periphery of a continuous cross-sectional body such as a cylinder or a prism formed from a tack-free material in which the fiber is impregnated with a resin. Material for compression molding of reinforced plastics.